Gas pipelines are used to transport natural gas over long distances. Compressor stations are positioned at intervals along the pipeline to pump the natural gas through the pipe. The gas flows by expanding in the pipe from the discharge of one compressor to the suction side of the next compressor.
The compressors used in the stations are configured to run continuously, but may need to be shutdown periodically. Typically, when shutdown, the compressor is isolated by closing valves upstream and downstream of the compressor. In some instances, the gas in the compressor and in the pipe between the valves is vented to atmosphere. In other situations, the compressor may be placed in a pressurized hold in which the gas pressure is maintained in the compressor and in the pipe between the valves. Due to the high pressure of the gas, however, some gas may leak to atmosphere past the dry seals in the compressor. Both venting gas to atmosphere and allowing high pressure gas to leak from the compressor seals to atmosphere is wasteful and environmentally unfriendly.
The fluid compression system of the present disclosure addresses one or more of issues set forth above.